OFV1000 – Rytons Over Facia Ventilator (1m L)

General Details

OFV1000 – Rytons Over Facia Ventilator (1m L)

  • Over facia ventilator.
  • Fixed to the top of the facia board or top course of brickwork to introduce air into the roof void.
  • For roof pitches 15° or greater.
  • Front fins prevent roof felt blocking the ventilation slots.
  • Unseen when the roof is completed.
  • 4mm ventilation slots promote unrestricted air flow and prevent the entry of birds and large insects.


  • 1m L x 44mm W x 20mm H (see image gallery above).
  • CAD drawing available by email.

Free Area:

  • 11,235mm² per length / metre.
  • Equivalent to a continuous 10mm venting gap.


  • Black.


  • Polypropylene.


  • Fix to the top of the facia board, or top course of brickwork, through the pre-formed slots across the top of the ventilator.
  • For a mono-pitch abutment installation first create a void by securing a softwood timber upstand to the roof timbers at the abutment (maintaining a gap of at least 5mm with the wall).

Handling Information:

  • Box quantity: 50 lengths.
  • Box size: 102cm W x 12cm H x 35cm D.
  • Box weight: 4.5kg.

Reference Material:

  • British Standard BS 5250.
  • The Building Regulations, Approved Document C.
  • The Building (Scotland) Regulations, Mandatory Standard 3.15.
  • The Building Regulations (Northern Ireland), Technical Booklet C.
  • NHBC Standards, 7.2 Pitched Roofs.

NBS Plus Specification: